In order to solve the problem of objectively evaluating recommendation trust using the weight of third party’s recommendation in the development of a solution for access control in open networks, a method of recommended trust evaluation based on the gray correlation analysis is proposed, which uses grey correclaton analysis theory between the entities of the development trend of the different degree to evaluate recommended weight in open network. Examples and simulation experiments show that results derived from the computation of the weight of the recommending entity is consistent with the actual results, which helps to verify that the proposed method can ensure the effectiveness and objectiveness of the evaluation decision on recommendation trust.